Living in northern Germany (read Hamburg) I can only agree.
That last winter here was very difficult for me, too. Especially the long, grey and dark weeks, without so much than a glimpse of sunshine.
Not very good for me. What has helped me, at least a little bit, was, that I started dancing again. Having someone else, who's "training" depends on you makes it less likely, that you do not go. And dancing is quite actually really strenuous, if done right and a lot of fun.
I learned to listen to my body, learned to feel my body better and now have at least two days a week, when I come home relaxed, lucky-exhausted.
But not everything is good. I feel, that "winter is coming". I can feel the energy withdrawing to a place deep inside me. I feel like curling up and preparing for hibernation. But that is not possible. I have to do my best at work everyday. So hibernating is not an option ;-)
So I wish all of you out there well. Be it SAD or be it "just" the "winter blues" be well and take care of yourself.